Toilet bars based on soap (alkali metal salts of fatty acids) are commonly used for cleansing the human body. A wide variety of additives have been suggested for inclusion in toilet bars. Some enhance the physical properties of the bar (hardness, wear rate, resistance to water). Others enhance the in-use properties of the toilet bar (lather characteristics such as volume and texture), and some impact on the impression the bar has on the skin both during washing (bar feel) and afterwards.